Iran has reportedly confirmed the commencement of the delivery of a powerful anti-aircraft missile defense system from Russia.

Deputy Head of the National Security and Foreign Policy Commission in Iran's Majlis (parliament) Ismail Kowsari said Sunday that Tehran has reached an agreement with Moscow on the delivery of the advanced S-300 surface-to-air missile system after years of negotiations.

"The missile system would be used to enhance Iran's defense capabilities and to protect the country's sovereignty," Kowsari told IRNA.

The confirmation came after Haaretz reported on Tuesday that Israel would send the head of political military policy in the Israeli Defense Ministry, Major General Amos Gilad, to press the Kremlin not to supply Iran with S-300 missile defense systems.

The Iranian official responded, however, that Israeli reactions to Tehran-Moscow military cooperation would not affect the deal.

Later on Wednesday, Russia announced that it is fulfilling the controversial deal and would deliver the anti-aircraft system to Iran.

"Moscow has earlier met its obligations on supplying Tor-M1 systems to Iran and is currently implementing a contract to deliver S-300 systems," RIA Novosti quoted an unnamed Russian source as saying.

Western countries have criticized Russian sales of defensive military equipment to Iran, saying that such deals have sabotaged efforts to retard Iranian nuclear progress.

The advance version of the S-300 system, the S-300PMU1 (SA-20 Gargoyle), can intercept 100 ballistic missiles and aircraft at once, at low and high altitudes within a range of over 150 kilometers.

According to intelligence officials familiar with the defense capabilities of the S-300, the missile system would effectively rule out an Israeli war against Iran.

"If Tehran obtained the S-300, it would be a game-changer in military thinking for tackling Iran," says long-time Pentagon advisor Dan Goure.

The US and Israel accuse Iran of making efforts to build a nuclear weapon and have threatened to launch air strikes on Iranian nuclear facilities.

In preparation for military action against Iran, Israel carried out a major military exercise earlier in June.

According to a report by the New York Times, more than 100 Israeli F-16 and F-15 fighters participated in the maneuvers over the eastern Mediterranean and Greece.

Later reports claimed that Greece, which is equipped with the same version of the S-300 surface-to-air missile system, assisted the Israeli Air Force in studying the system.